When the first transferable mobile phones, weighing several kilograms each, entered into the market, they had two basic uses. The transferable mobile phones were used either fixed to the vehicle and normally equipped with an external vehicle antenna attached to the vehicle's roof or they were used outside the vehicle by means of a so-called whip antenna attached to the mobile phone. The antenna connection was implemented by means of a coaxial connector often by using a BNC or Baby "N" Connector, known to persons skilled in the art. Coaxial connections to mobile phone antennae are described e.g. in patent publications EP 407 145, WO 96/27916 and U.S. Pat. No. 5,551,080. In a vehicle installation, the antenna connection from the mobile phone, e.g., to the vehicle's roof antenna was implemented by means of a coaxial cable according to FIG. 1A. When it was necessary to use the transferable mobile phone outside the vehicle, the cable running to the roof antenna was unscrewed and a whip antenna was installed in its place as shown in FIG. 1B. These systems are still commonly used. It is true that this kind of antenna solution, based on the use of coaxial connectors, functions well in this environment. Transferable mobile phones' big size and, at the time, high price did not prevent, e.g., the use of big and expensive Baby "N" Connectors. FIGS. 1A and 1B will be described later in more detail.
The transferable mobile phones were so heavy that they were not detached from the car and re-installed on a daily basis. Thus, it was not necessary to detach and attach the troublesome antenna connector very often. However, the situation changed completely when light, pocket-size mobile phones started to become more common. People began to carry their mobile phones with them and, therefore, there was no sense in screwing an antenna connector in place, when getting in the car, and then unscrewing it again, when getting off the car. On the other hand, a big BNC-type coaxial connector would no longer have fitted in the small mobile phone anyway. Neither would it have been sensible for economic reasons.
A solution that is still being used was found for the problem presented above. Normally, a fixed whip antenna is used in portable mobile phones. When a mobile phone is attached, e.g., to a vehicle, this is done through a separate installation mount. In this case, the fixed antenna switches off and an external vehicle antenna switches on, typically, by means of a separate antenna connector, installed on the mobile phone's bottom, and a counterpart, fixed to the installation mount, as shown in FIG. 2. An antenna selector is responsible for switching between the antennas. This system operates well in practice, because the mobile phone can be easily detached from and attached to the installation mount, and the antenna is selected automatically. The system's drawbacks are a connection loss in the antenna selector, as well as the use of a small coaxial connector the manufacturing costs of which are high, in connection with an external antenna. In addition, high manufacturing accuracy is required of the installation mount, because the small coaxial connector should go exactly in the right place, when the mobile phone is attached to its installation mount. In addition, the small coaxial connectors are sensitive to dirt, wearing and they are also easily broken. The solution also presupposes additional components, such as an antenna selector. FIG. 2 will be described later in more detail. The systems presented above are applicable to their own special uses. Now that the integration of electronics has developed further, it has become possible to further reduce the size of telecommunications terminals and mobile stations utilising radio communication. Radio modules or mobile stations, coupled to portable computers, by means of which a portable computer can be connected to telecommunications networks wirelessly using radio communication, are becoming an important application. A radio module is coupled to a portable computer through a data bus, e.g., a PCMCIA (Personal Computer Memory Card International Association) bus, which is currently the most commonly used bus. It is possible to install, in the PCMCIA bus, a PCMCIA card about the size of a credit card, whereon the electronic components required by the radio module can be installed. However, the PCMCIA card's small physical measurements set strict limits to the components to be used in connection with the PCMCIA card. The implementation of an antenna has proved extremely problematic, because it has been impossible to implement a small and reliable antenna connection. In addition, solutions based, e.g., on small coaxial connectors are expensive to implement due to the accuracy required of the fine-mechanical parts and they also break easily. Due to the measurements, the centre pin of a small coaxial connector remains thin and weak. Therefore, this type of connector is not suitable for use in very small radio modules, e.g., the size of a data card, wherein the antenna must often be turned from one position to another. A thin and weak centre pin wears and does not guarantee reliable contact for an antenna signal.
In Patent Publication EP 0 610 025 A1, a solution has been presented, wherein a PCMCIA card modem has been implemented, the card modem consisting of two or more modules, substantially the size of a PCMCIA card, which have been articulated with one another. The antenna used has been integrated on the surface of a circuit board within a module located outside a computer. The solution used requires a complex mechanical structure between the different modules and is unsuitable for small radio modules the size of only one PCMCIA card. In addition, the implementation of an antenna within the same module on the same circuit board as the rest of the electronics causes a problem in the form of radio interference and the deterioration of the antenna's radiation properties. In addition, an arrangement according to said publication does not enable a separate external antenna to be coupled in connection with a data card.